ANALYSIS OF DNA PLOIDY HETEROGENEITY IN PROSTATE CANCER

The objectives of this study were to assess DNA ploidy heterogeneity and thus the specificity of digital cytometry for prostate adenocarcinoma, as intratumoral variation of DNA content is believed to exist among these cells, as occurs with histological differentiation. Fifteen prostate adenocarcinoma patients were selected. They underwent radical prostatectomy and the tissue obtained had 3 distinct areas analyzed to determine cellular ploidy and tumor grade (Gleason score). Statistical analysis has described the values in the Gleason score in the different areas, both in the diploid and aneuploid groups, in relation to average, standard deviation, median, and maximal and minimum values. The prostatic tissue studied showed only diploid tumors in some patients and only aneuploid tumors or an association between diploid and aneuploid tumors in others. There were 11 tumors where the areas were diploid (73.3%), 3 aneuploid tumors (20%) and a tumor with 2 diploid areas and an aneuploid one (6.7%). There was thus homogeneity among the areas studied in 93.3% of the prostatic tumors. The values in the Gleason score were compared with the ploidy of each area in the several tumors. The average of values in the Gleason score in the tumor areas of the diploid group was significantly smaller (p < 0.05) than the observed average in the areas of aneuploid group of tumors. This relationship occurred globally in the areas of tumors. In conclusion, ploidy analysis of the cellular DNA in prostate adenocarcinoma through digital cytometry shows high specificity (93,3%) and cellular differentiation rate was significantly lower in diploid tumors.